RU2815044C1 - Multilayer paper cartridge case for smooth-bore gun cartridges - Google Patents

Abstract

FIELD: weapons and ammunition.

SUBSTANCE: invention relates to ammunition of smooth-bore weapons and can be used for firing from smooth-bore weapons of central fire. Multilayer paper assembly sleeve with bottom wad height equal to the height of the metal base with accuracy of ± 0.5 mm, consists of a paper tube clamped between the bottom wad and the metal base, and rolled from coils—layers of paper with thickness of 130 ÷ 170 mcm, and having temporary resistance δ (kgf/cm²) not less than 9 in machine direction and 5 in transverse direction and relative elongation ε (%) of not less than 3 in machine direction and 7 in transverse direction. Sleeve tube is made with the number of turns—layers N for each gauge by winding on the spindle of N pieces of full turns—layers of paper. Number N is calculated by derived mathematical formula Ni=(H−Bi)/2C, where Bi is the inner diameter of the barrel bore, H is the inner diameter of the chamber at the end of the cartridge chamber, C is the thickness of the paper, where i=1 for the lower—small values of the half-range of values of the inner diameter of the channel of the smooth-bore weapon of the central fire, and i=2 for upper—large values of half-range of values B2 of inner diameter of channel of smooth-bore weapon of central strike. Also disclosed is a multilayer paper assembly sleeve with a bottom wad height less than the height of the metal base.

EFFECT: enabling the possibility of creating a multilayer paper assembled cartridge case for cartridges of various calibers with an inner diameter as close as possible to the smooth-bore gun barrel inner diameter, for which it is intended and which has all full turns—layers of paper, to ensure high accuracy and sharpness of fire and to exclude the possibility of increasing pressure of powder gases in the chamber of the weapon during firing.

4 cl, 1 dwg, 3 tbl

Description

The invention relates to the field of ammunition for smooth-bore weapons and can be used for firing from smooth-bore weapons of central firing

A known paper prefabricated cartridge case for sporting and hunting cartridges, consisting of a paper tube, a bottom wad and a metal base [V.N. Trofimov "Hunting ammunition", M.: Ruchenkina, p. 20]. The tube of this cartridge case is formed by winding 6-7 full layers of grade A cartridge paper onto a spindle according to GOST 876-73. This sleeve design is chosen as an analogue.

The disadvantage of the design of such a sleeve is its insufficient strength to ensure the safety of shooting from modern smooth-bore shotguns, including self-loading ones, with chamber sizes that meet the requirements of Table VII of the TRPP PMK and GOST R 50530-2015, which was developed based on the decisions of the Permanent International Test Commission (PIC) handguns. This GOST contains requirements for mutual compliance with the dimensions of the weapon’s chamber and cartridge (and therefore the cartridge case), formalized in the form of Table VII of the TRPP PMK “Calibers of cartridges for smooth-bore weapons and calibers of smooth-bore weapons of the central fire”. The requirements of Table VII of the TRPP PMK combine the cartridge case, cartridge and smooth-bore center-fire weapon into one Complex.

Previously, paper cartridges produced in Russia from cartridge paper grade A according to GOST 876-73 for cartridges had low dynamic strength and often collapsed under conditions of short-term loading in the chamber of a gun during a shot, which lasts about 2 ms.

A known paper prefabricated cartridge case for cartridges for shotguns, consisting of a paper tube, a bottom wad and a metal base [Kislin M.A. and others. “High-strength paper cartridges for cartridges for smooth-bore guns.” Scientific and technical journal “Ammunition and high-energy condensed systems”, Department of the Industry of Conventional Arms, Ammunition and Special Chemicals of the Ministry of Industry and Trade of the Russian Federation, Moscow, 2014; RF Patent No. 2197703, 2001], which is taken as a prototype. The tube of this sleeve is formed by winding stronger paper onto a spindle than paper grade A, used similarly; in particular, high-strength electrical insulating cardboard EV-0.15 in accordance with GOST 2824-86 can be used.

The advantage of the prefabricated paper cartridge case known from the prototype is that it is environmentally friendly, and plastic cartridge cases, which are currently widely used to equip hunting cartridges for shotguns, are harmful to the environment. Plastic has become a real epidemic of the 21st century. It is found everywhere: plastic dishes, bags, packaging, etc. and undoubtedly plastic cartridge cases that end up in the environment when shooting while hunting. A person, without any doubt, encounters this material every day. Plastic pollution can also poison animals, which in turn can negatively impact the human food supply. More than 260 species of animals are known to accidentally ingest plastic. Plastic pollution currently comes in many forms, including water pollution (waste entering rivers, lakes, seas and oceans). The average decomposition time for plastic products created using various technologies ranges from 6 months to 700 years.

In addition, the sleeve known from the prototype can be used at ambient temperatures down to -50°C, and for plastic sleeves the use is limited to ambient temperatures not lower than -20°C. However, at present in Russia the production of paper cartridge cases has not deservedly been curtailed (there is not a single manufacturer), despite the fact that JSC NMZ Iskra, Novosibirsk, received a letter of gratitude from the Minister of the Republic in the early 2000s Sakha (Yakutia) for “the production of an environmentally friendly paper sleeve, known from the prototype, and concern for the preservation of our native nature for future generations.”

A disadvantage of the design of the paper sleeve according to the prototype is that the inner diameter of the sleeve is not determined by the number of complete turns (layers) of paper of a given thickness used for its manufacture, for example, electrical insulating cardboard EV-0D5 according to GOST 2824-86, having a thickness of (130÷170) microns . This circumstance does not make it possible to ensure maximum equality of the internal diameter of the cartridge case and the internal bore of the barrel of a center-fire firearm during a shot for each caliber of a smooth-bore center-fire weapon given in Table VII of the TRPP PMK. Changing the number of complete turns (layers) of paper (or electrical insulating cardboard) significantly changes the thickness of the shell wall, and therefore the internal diameter of the shell, which, based on modern requirements for the safety and quality of firing a shot shell during a shot, should be as close as possible to the internal diameter bore of a smooth-bore center-fire weapon for which this sleeve is intended. In addition, a disadvantage of the sleeve known from the prototype is that the turns (layers) of the wound paper may not be complete, i.e. The length of the paper in each turn is not equal to the circumference of the surface on which it is wound. Therefore, the paper sleeve tube has a different wall thickness around its circumference, which worsens the quality of the ballistic parameters of the shot.

From the analysis of data presented in the work of Blum M.M. and Shishkina I.B. [Blum M.M., Shishkin I.B. Hunting weapon. Directory. Agropromizdat, 1987], we can conclude that the more accurately the dimensions of the internal channels of the cartridge case and the barrel coincide at the moment of the shot, the better the quality of the shot (accuracy and uniformity of the shot scree) and the sharper the shot of the smoothbore gun. On the contrary, the smaller this coincidence, the more fluctuations in the quality and sharpness of the shotgun’s shotgun fire should be expected from shot to shot. In addition, a cartridge bore that is too wide relative to the bore leads to an increase in the pressure of the powder gases, which can lead to rupture of the gun barrel, especially with fast-burning (sharp) varieties of smokeless powder used to load cartridges. This work indicates that the length of the transition cone from the chamber to the barrel when using paper cartridges should be from 1.5 to 6 mm. But the recommended size is 1.5mm. Indeed, at such a distance (the length of the transition cone), the shot will not change significantly if the internal diameter of the cartridge case is equal to the internal diameter of the barrel.

The technical objective of the invention is to create a design for a multi-layer paper prefabricated cartridge case for cartridges for smooth-bore centerfire weapons of various calibers with an internal diameter as close as possible to the internal diameter of the bore of the smooth-bore weapon for which it is intended, and which has all full turns (layers) of paper to ensure high indicators of accuracy and sharpness of combat of smooth-bore weapons and eliminating the possibility of increasing the pressure of powder gases in the chamber of a smooth-bore weapon when fired.

The problem is solved by:

Option 1 design. Multi-layer paper composite sleeve for cartridges for smooth-bore weapons of the central fire with the height of the bottom wad equal to the height of the metal base with an accuracy of ±0.5 mm, consisting of a paper tube pinched between the bottom wad and the metal base and rolled up from several layers of paper with a thickness (130÷170 ) microns and having a temporary resistance σ (kgf/cm ² ) of at least 9 in the machine direction and 5 in the transverse direction and a relative elongation ∈ (%) of at least 3 in the machine direction and 7 in the transverse direction with the sleeve tube, manufactured in two versions with a different number of turns (layers) N of paper for each caliber of a smooth-bore weapon wound on a spindle N pieces of full turns (layers) of high-strength paper, while the number N is calculated by the formula: N _i = (HB _i )/2C, where: B _i - internal bore diameter according to Table VII TRPP PMK; N is the internal diameter of the chamber at the end of the chamber according to Table VII of the TRPP PMK; C - paper thickness; i=1 for the lower (small values) range of values B ₁ of the internal diameter of the channel of a smooth-bore weapon of the central fire of each, presented in Table VII of the TRPP PMK; i=2 for the upper (large values) range of values B ₂ of the internal diameter of the channel of a smooth-bore weapon of the central fire of each, presented in Table VII of the TRPP PMK.

Option 2 design. Multilayer paper composite cartridge case for cartridges for smooth-bore weapons of the central fire, in which the height of the bottom wad is less than the height of the metal base, consisting of a paper tube pinched between the bottom wad and the metal base and rolled up from several layers of high-strength paper, approximately thick (130÷170) μm and having a temporary resistance σ (kgf/cm ² ) of at least 9 in the machine direction and 5 in the transverse direction and a relative elongation ∈ (%) of at least 3 in the machine direction and 7 in the transverse direction and a sleeve tube made in two versions with different number of turns for each caliber by winding onto a spindle N pieces of full turns (layers) of paper, while the number N is calculated by the formula: N _i = (Н-B _i )/2С, where: B _i is the internal diameter of the barrel bore according to Table VII of the TRPP PMK; N is the internal diameter of the chamber at the end of the chamber according to Table VII of the TRPP PMK; C - paper thickness; i=1 for the lower (small values) range of values B _{1 of} the internal diameter of the channel of a smooth-bore weapon of the central firing of each, presented in Table VII of the TRPP PMK caliber; i=2 for the upper (large values) range of values B ₂ of the internal diameter of the channel of a smooth-bore weapon of the central fire of each caliber presented in Table VII of the TRPP PMK, is made with a metal base wall thickness h less than the critical value h _cr , selected according to the empirical formula h≤h _кp =(2σ/σ _t )⋅С, where σ _t is the fluidity resistance of the base metal; σ - temporary resistance of paper in the transverse direction; C is the wall thickness of the paper tube.

In both versions of the design of a multilayer paper prefabricated sleeve, it is possible to manufacture it by rolling up a tube from several full turns (layers) of electrical insulating cardboard EV-0.15 in accordance with GOST 2824-86 with a thickness of 130 to 170 microns. Analysis of the data given in Table VII of the TPPP PMK, shows that the full range of the "B" value of the internal diameter of the barrel of each caliber is quite large. For example, it is equal to 0.5 mm for calibers 14, 16, 20, 24, 28, 32 and 410 and 0.7 mm for calibers: 4, 8, 10 and 12. This means that for each caliber of a smooth-bore weapon it is necessary to make two paper cartridges with different inner diameter. Therefore, in order to complete the task of creating a design for a multilayer paper prefabricated sleeve with an internal diameter as close as possible to the internal diameter B of the bore of a smooth-bore weapon for which it is intended, the full range of “B” values was divided for each into two half-ranges B ₁ and B ₂

The specific values of these ranges: full B, lower B ₁ (small values) and upper B ₂ (large values) values of the internal diameter of the barrel of a smooth-bore center-fire weapon are given in Table 1.

The essence of solving the problem is illustrated in Fig. 1, which presents the design (design option 1) of a multilayer paper prefabricated sleeve located in the chamber of a smooth-bore center-fire weapon, for the case when the height of the bottom wad 1 is equal to the height of the metal base L (L=1). The proposed cartridge case consists of a metal base 1, a bottom wad 2 and a tube 3 sandwiched between them, wound from high-strength elastic paper with a thickness of 130 to 170 microns with a number of full turns ensuring that the internal diameter of the cartridge case at the moment of firing coincides with the internal diameter of the barrel. Between the sleeve tube 3 and the chamber 6 there is an initial gap 5, and between the metal base 1 and the chamber 6 there is an initial gap 4.

The external geometric dimensions of the elements of the sleeve during its manufacture are provided by: a paper tube - a calibration matrix, through which the tubes are passed after manufacturing and drying to a given humidity of 5-8%; metal base - the size of the press tool for the line of cartridge heading (LOG). In this regard, due to the existing technological process for manufacturing prefabricated paper cartridges at cartridge factories, it turns out that the diameters of the tube and the metal base on the final manufactured cartridge are different. This leads to the appearance of different sizes of initial gaps between the chamber and various elements of the sleeve (tube and base). For example, for a 12-gauge case, the maximum initial clearance between the tube and the chamber is 0.25 mm. When calculating this initial gap, the dimensions of the chamber of a 12-gauge centerfire smoothbore shotgun were taken in accordance with Table VII of the TRPP PMK and GOST R 50530-2015.

Multilayer paper prefabricated sleeve of design 1 (L=1), shown in Fig. 1, as part of a cartridge, works as follows: after initiation of the igniter primer (KB) and ignition of the powder charge in the cartridge, due to the pressure of the powder gases and detonation products KB, elastic expansion of the walls of the paper tube 3 occurs until it comes into contact with the chamber 6 of the gun.

For a multi-layer paper prefabricated sleeve of design 2 (L≥1), the operation of the sleeve is different: after initiation of the CV and ignition of the powder charge in the cartridge, not only elastic expansion of the walls of the paper tube 3 occurs, but also plastic expansion of the thin-walled metal base 1. Therefore, the dynamic strength of the sleeve is affected and ductility of the metal base. With a rigid, non-plastic metal base, during the expansion of the paper tube when fired, it is cut (destructed) by the edge of the metal base. Severance of the cartridge case tube is especially dangerous for the shooter, because Remnants of the tube may become stuck in the barrel, which can lead to damage to the gun and injury to the shooter during the next shot. Based on experimental and theoretical work carried out at JSC NMZ Iskra [RF Patent No. 2197703], the empirical formula h≤h _kp = (2σ/σ _t )⋅s was derived, where σ _t is the fluidity resistance of the base metal; σ - temporary resistance of paper in the transverse direction; C is the wall thickness of the paper tube, which determines the critical thickness h _kp of the metal base of the sleeve, below which trimming of the sleeve tube does not occur.

A paper cartridge case (for example, 12 gauge) as part of a cartridge works as follows. After initiation of the igniter capsule and ignition of the powder charge, due to the pressure of the powder gases, the walls of the paper tube elastically expand until it comes into contact with the chamber of a 12-gauge smoothbore shotgun, the internal size of which, according to Table VII of the TRPP PMK, is 20.3 mm. At this moment, the internal diameter of the sleeve becomes equal to 20.3 mm minus twice the “C” value of the wall thickness of the paper tube intended for a 12-gauge shotgun.

To calculate the number of complete turns (layers) of paper in the cartridge case tube, which ensures maximum equality of the internal diameter of the cartridge case at the moment of firing with the internal diameter of the barrel, a mathematical formula is derived:

N _i =(Н-B _i )/2С, where: B _i is the internal diameter of the barrel bore according to TRPP PMK; N - internal diameter of the chamber at the end of the chamber according to the TRPP PMK table; C - paper thickness; i=1 for the lower (small values) range of values B ₁ of the internal diameter of the channel of a smooth-bore weapon of the central fire of each caliber presented in the TRPP PMK; i=2 for the upper (large values) range of values B ₂ of the internal diameter of the channel of a smooth-bore weapon of the central fire of each caliber presented in the TRPP PMK.

Using the derived formula, the number of full turns of paper with a thickness of 130 to 150 microns in the cartridge tube was calculated for various calibers of smooth-bore center-fire weapons. In this case, the full range B of the internal diameter of the channel of each of the 11 selected calibers a of smoothbore weapons was divided into two half-ranges B ₁ and B ₂ , which are shown in Table 1.

The calculation results are shown in tables 2 and 3.

Analysis of the data presented in tables 2 and 3 shows the correctness of the need to select two half-ranges of the internal diameter of the barrel for each caliber of a center fire firearm. For every caliber

For smoothbore weapons, to ensure maximum equality of the inner diameter of the cartridge case at the moment of firing with the inner diameter of the barrel, it is necessary to use a multilayer paper tube with a different number of turns. For example, for a 12 gauge, for a small value of the internal diameter of the barrel (conditionally 18.40 mm), you need to wind a tube of 7 turns (layers), and for a larger value of the internal diameter of the barrel (conditionally 18.70 mm), you need to wind a tube of 6 turns (layers). It is important to note that, based on experience, it has been established that if the number of layers (turns) in a paper tube becomes less than four, this significantly reduces the reliability of the paper cartridge in the chamber of the gun when fired. However, as can be seen from the data in Tables 1 and 2, the selected paper thickness from 130 to 170 microns meets this requirement.

In practice, after the implementation of the proposed invention, a hunter or athlete who owns a 12-gauge smoothbore weapon must know the internal diameter of the bore. If this diameter is close to the values (18.70÷18.9) mm, he will buy paper sleeves or cartridges with the number of complete turns (layers) - 6, and in the case when the diameter is close to the values (18.2÷18.40 ) mm - with the number of complete turns (layers) - 7.

Tests for dynamic loading of multilayer paper prefabricated sleeves made of electrical insulating cardboard EV-0.15 with a thickness of 150 microns were carried out according to the dynamic hydraulic testing technique specially developed at JSC NMZ Iskra. 44-2000.

Analysis of dynamic hydraulic tests showed a significant increase (approximately 2 times) in the dynamic strength of 12-gauge paper sleeves when replacing grade A paper with EV-0.15. In addition, prototypes of 12-gauge paper cartridges from EV 0.15, having L=1, were subjected to strength tests in ballistic guns and self-loading hunting rifles in accordance with TU 7272-002-07513903-99 "Paper and plastic cartridges" and GOST R50530 "Types and methods of control during certification tests for safety." Multilayer prefabricated paper cartridges of 12 gauge made of electrical insulating cardboard EV 0.15 after firing from a ballistic gun MTs-16-12 with an increased maximum pressure of powder gases during firing (800-1000 kgf/cm ² ) had no defects and met all technical requirements conditions. Moreover, the tests were carried out both after holding the cartridges at normal temperature for 4 hours, and after holding two different batches of cartridges at temperatures of +50°C (one batch) and -50°C (another batch) for 4 hours .

Multilayer paper cartridges made from electrical insulating cardboard EV 0.15 were also tested by shooting from a self-loading hunting rifle MTs-21-12 with control of the accuracy and uniformity of shot scree at a distance of 35 m. The test results showed the absence of defects in the cartridges and the absence of delays in the operation of the self-loading rifle, as well as compliance of shot shower parameters with modern requirements. In the case when the design of a multilayer paper prefabricated sleeve is made according to option 2 (L>1), its dynamic strength is affected by the ductility of the metal base. With a rigid, non-plastic base, during the expansion of the tube during a shot, it is trimmed (destructed) by the edge of the metal base. For multi-layer prefabricated paper sleeves of 12 gauge from EV 0.15, having six full turns (layers) and σ = 5 kgf/mm ² , with a metal base, which has σ _t = 30 kgf/mm ² according to the formula h _kp = (2σ/σ _t )⋅s, where σ _t is the fluid resistance of the base metal;

σ - temporary resistance of paper in the transverse direction;

C - the wall thickness of the paper tube was determined h _kp = 0.30 mm.

Tests of multilayer paper prefabricated cartridge cases with L>1 confirmed that with a metal base thickness h of 0.5 mm, the case tube is trimmed during a shot with a subsequent violation of its integrity; with a thickness h of 0.3 mm, this does not happen. This confirms the need to select the correct thickness of the sleeve base. Currently, work is underway to produce sleeves with a thinner base.

Multilayer prefabricated paper cartridges according to the proposed invention, before being sold to the consumer at JSC NMZ Iskra, must be subjected to strength tests in ballistic guns and self-loading hunting rifles in accordance with TU 7272-002-07513903-99 "Paper and plastic cartridges", developed at JSC " NMZ "Iskra", and GOST R50530 "Types and methods of control during certification tests for safety."

Claims (31)

1. Multi-layer paper composite sleeve for cartridges for smooth-bore weapons of the central fire with the height of the bottom wad equal to the height of the metal base with an accuracy of ±0.5 mm, consisting of a paper tube pinched between the bottom wad and the metal base, and rolled up from coils - layers of paper thickness 130÷170 microns, and having a tensile strength σ (kgf/cm ² ) of at least 9 in the machine direction and 5 in the transverse direction and a relative elongation ∈ (%) of at least 3 in the machine direction and 7 in the transverse direction, characterized in that that the sleeve tube is made with a number of turns - layers N for each caliber by winding onto a spindle N pieces of full turns - layers of paper, while the number N is calculated using the derived mathematical formula N _i =(HB _i )/2C, where B _i is the internal diameter of the bore, N is the inner diameter of the chamber at the end of the chamber, C - paper thickness, where i=1 for the lower - small values of the half-range of values B ₁ of the internal diameter of the channel of a smooth-bore weapon of the central fire, and i=2 for the upper - large values of the half-range of values B ₂ of the internal diameter of the channel of a smooth-bore weapon of the central fire. 2. Multi-layer paper prefabricated cartridge case for cartridges for smooth-bore center-fire weapons according to claim 1, characterized in that the tube is rolled up from several full turns - layers of N pieces of electrical insulating cardboard EV-0.15 with a thickness of 130÷170 microns, and depending on calibers of smoothbore weapons, the number N is equal to: - for the 4th caliber N ₁ =10, N ₂ =9; - for 8 gauge N ₁ =8, N ₂ =7; - for 10th, 12th, 14th calibers N ₁ =7, N ₂ =6; - for 16th, 20th, 24th, 28th calibers N ₁ =6, N ₂ =5; - for 32nd, 410th caliber N ₁ =5, N ₂ =4. 3. Multi-layer paper prefabricated cartridge case for cartridges for smooth-bore weapons of the central fire, consisting of a paper tube, pinched between the bottom wad and a metal base, and rolled up from several layers of paper with a thickness of 130÷170 microns, and having a temporary resistance σ (kgf/cm ² ) not less than 9 in the machine direction and 5 in the transverse direction and relative elongation ∈ (%) not less than 3 in the machine direction and 7 in the transverse direction, characterized in that the sleeve tube is made with N number of complete turns - layers of paper, with the number N calculated using the derived mathematical formula N _i =(HB _i )/2C, where B _i is the internal diameter of the bore, N is the inner diameter of the chamber at the end of the chamber, C - paper thickness, where i=1 for the lower - small values of the half-range of values B ₁ of the internal diameter of the channel of a smooth-bore weapon of the central fire, and i=2 for the upper - large values of the half-range of values B ₂ of the internal diameter of the channel of a smooth-bore weapon of the central fire, and the height of the bottom wad is less than the height of the metal base, and the wall thickness of the metal base h is less than the critical value h _kp , selected according to the empirical formula h≤h _kp =(2σ/σ _t )С, where σ _t is the fluid resistance of the base metal, σ - temporary resistance of paper in the transverse direction, C is the wall thickness of the paper tube. 4. Multilayer paper prefabricated sleeve for cartridges for smooth-bore center-fire weapons according to claim 3, characterized in that the tube is made of several full turns - layers of N pieces of electrical insulating cardboard EV-0.15 with a thickness of 130÷170 microns, and depending on calibers of smoothbore weapons, the number N is equal to: - for the 4th caliber N ₁ =10, N ₂ =9; - for 8 gauge N ₁ =8, N ₂ =7; - for 10th, 12th, 14th calibers N ₁ =7, N ₂ =6; - for 16th, 20th, 24th, 28th calibers N ₁ =6, N ₂ =5; - for 32nd, 410th caliber N ₁ =5, N ₂ =4.

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